Configuring snapshots and backups

By bringing backups back to the data center, the Core eliminates the requirement and infrastructure of running backups at the remote branches. Data from the branch is always synced back to the data center so you can schedule application-consistent backups of the branch VMs. Once the snapshot request reaches the data center, the Core triggers the application-consistent snapshot on the supported array and automatically mounts the snapshot to a proxy host. The backup software on the storage array can then perform the backups through the proxy host in the data center.

In the context of snapshots, backups, and data protection in general, there are two types or states of data consistency:

• Crash consistency - A backup or snapshot is crash consistent if all of the interrelated data components are as they were (write-order consistent) at the instant of the crash. To better understand this type of consistency, imagine the status of the data on your PC’s hard drive after a power outage or similar event. A crash-consistent backup is usually sufficient for nondatabase operating systems and applications like file servers, DHCP servers, print servers, and so on.

• Application consistency - A backup or snapshot is application consistent if, in addition to being write-order consistent, running applications complete all their operations and flush their buffers to disk (application quiescing). Application-consistent backups are recommended for database operating systems and applications such as SQL, Oracle, and Exchange.

SteelFusion ensures continuous crash consistency at the branch and at the data center by using journaling and by preserving the order of write operations across all the exposed LUNs. For application-consistent backups, you can directly configure and assign hourly, daily, or weekly snapshot policies. Edges interact directly with both VMware ESXi and Microsoft Windows servers, through VMware Tools and VSS, to quiesce the applications and generate application-consistent snapshots of both VMFS and NTFS data drives.

Note: When using Windows server clients, dynamic disks will be excluded during backup. Ensure that the corresponding Edge and Riverbed Host Tools in Windows are updated at the branch.